FIG. 1 is a block diagram of a conventional video processing subsystem of a communication device such as such as a mobile telephone, personal digital assistant (PDA) or a hybrid thereof. Referring to FIG. 1, there is shown a camera 102, CPU 104, DISPLAY 106, storage block 108, CODEC 110, and RGB-YUV block 112. The CPU 104, CODEC 110, and RGB-YUV block 112 may be packaged in an integrated circuit (IC) 114 or system-on-chip (SoC), for example.
The red, green and blue (RGB) color space represents the basic component analog signal set where a signal is utilized to represent each of the primary colors. A camera generates the three RGB colors and in a television or monitor, for example, the colors are added together in order to reproduce an image. The addition of the colors are referred to as primary additive color reproduction, and conforms to a three dimensional color coordinate system referred to as a RGB color cube. Although RGB is well known and widely utilized, it suffers from some drawbacks. For example, RGB requires the red, green and blue components to be of equal bandwidth in order to generate the colors within the RGB cube. As a result, frame buffers require the same depth and display resolution for each of the red, green and blue components. The YUV color space addresses some of the drawbacks RGB color space and utilizes luma (Y) and two color difference signals, namely, U and V. In this regard, U represents the difference between R and Y (R−Y) and V represents the difference between B and Y (B−Y). The U and V components are added so that a black and white television may properly represent a black and white image, which is normally represented by the luma (Y) component.
The display 106 may be, for example, a LCD panel that may be adapted to preview digital images that are captured by the camera 102. The display 106 may also be adapted to display image data that is previously stored in the storage block 108.
The storage block 108 may be any suitable memory such as a random access memory or flash memory for storing video.
The CODEC 110 may comprise suitable, logic and/or code that may be adapted to process video data and/or related audio data and store any resulting processed data in the storage block 108. The CODEC 110 is adapted to receive YUV formatted video for processing.
The RGB-YUV block 112 may comprise suitable logic, circuitry and/or code that may be adapted to convert RGB formatted video data received from the camera 102 to YUV formatted data, which may be directly processed by the CODEC 110.
In operation, the CPU 104 is adapted to receive RGB formatted video data at 15 frames per second (fps) and process it for display on the LCD panel 106 in the same RGB format. Since the CODEC 110 is adapted to receive YUV formatted video for processing, the RGB-YUV block 112 is used to convert the received native video format from RGB to YUV. Accordingly, the CPU 104 transfers received RGB formatted video to the LCD monitor 106 and, in conjunction with the RGB-YUV block 112, converts the RGB formatted video to YUV formatted video. The YUV formatted video is then communicated to the CODEC 110 for processing. The processed video output from the CODEC 110 may be stored in the storage block 108 for transmission or display.
The CPU 104 processes the received formatted video data on an image-by-image basis. In this regard, each image must be individually RGB and YUV processed by the CPU 104, which might include converting RGB formatted image data to YUV formatted image data by RGB-YUV 112. Individually processing each image for both RGB format and for YUV format is a computationally intensive task that requires a significant amount of CPU power and data transfer bandwidth. As a result, the whole system may easily become overloaded, resulting in reduced system performance.
Further limitations and disadvantages of conventional and traditional approaches will become apparent to one of skill in the art, through comparison of such systems with some aspects of the present invention as set forth in the remainder of the present application with reference to the drawings.